The present invention relates to a method of manufacturing a treatment instrument of an endoscope, and more particularly to a method of manufacturing which includes a step of connecting parts of the treatment instrument of the endoscope.
Most of the treatment instruments of an endoscope has a connected portions. For example, an instrument having an operation wire and forceps to be operated, there is a portion where an end of the wire is connected to a mechanism for moving the forceps. For another example, an instrument may have a portion to be bent easily and a portion which is formed to be relatively rigid. Such portions may be formed with coils made of thin wires and thick wires, respectively, and the flexible and rigid portions are soldered.
The soldered connection has, however, various disadvantages. For example, residual flux may corrode the coils, or when the coils are soldered, a positional relationship between the coils may change.
Japanese Utility Model Publication HEI 07-13692 disclosed a connecting structure in which a proximal end of a coil and a distal end of another coil are heat-melted by a laser beam, and then the melted portions are connected. In such a method, however, since the laser beam is used, the proximal end of one coil and the distal end of the other coil should contact without a clearance so that the laser beam does not leak therefrom. For this purpose, the end surfaces should be made flat by grinding, which requires an extra working process.
Another type of instrument is a brush instrument such as a cleaning brush for cleaning the instrument channel of the endoscope or a cytological brush for collecting tissues in the human cavity. The brush instrument includes an operation wire and a brush unit secured to the tip of the operation wire. Generally, the brush unit is made of synthetic resin, while the wire is made of metal. Since such a brush instrument is to be inserted through the instrument channel of the endoscope or human tissues, a collar is provided at the tip of the operation wire. Typically, the collar is fixed on the wire using solder, and sometimes a sufficient amount of the solder is provided to round the edges of the collar.
Since the collar is secured to the wire by soldering, residual flux may corrode the wire. Further, since the brush unit is formed of the synthetic resin, in order to avoid overheating of the brush unit, the soldering process should be done within a relatively short period of time, which sometimes makes it difficult to firmly secure the collar to the tip of the wire.
In view of the above, it is therefore an object of the present invention to provide an improved method of manufacturing treatment instrument of an endoscope, in which parts of the treatment instrument can be connected with a relatively simple method, without the disadvantages as above.
Another object of the invention is to provide a method of manufacturing instrument of an endoscope, in which the tip of a wire which is to be moved in the axial direction thereof is processed so as not to scratch or hurt the instrument channel of the endoscope, or human tissues.
According to an aspect of the invention, there is provided a method of manufacturing a treatment instrument of an endoscope, the treatment instrument including a first coil and a second coil that is different from the first coil and to be connected to the first coil, an operation wire, and a device secured to a distal end of the first coil, the wire being inserted through the first coil and the second coil, a distal end of the wire being connected to the device, the device being driven by the wire when the wire being moved in the first coil and the second coil. Such a method includes inserting one end of the first coil and one end of the second coil in a connection pipe from opposite ends thereof, and exposing ends of the connection pipe and portions of the first coil and the second coil corresponding to the ends of the connection pipe to arc columns, respectively. The portions exposed to the arc columns are melted, and thereafter, solidified.
Optionally, an outer diameter of the connection pipe member may be substantially the same as an outer diameter of the first coil outside the connection pipe and an outer diameter of the second coil outside the connection pipe, and an inner diameter of the connection pipe member may be substantially the same as an outer diameter of the first coil inside the connection pipe and an outer diameter of the second coil inside the connection pipe.
Further optionally, a plurality of positions, along a circumferential direction, of a portion where an end of the connection pipe is to be connected to the first coil are exposed to arc columns, respectively, and a plurality of positions, along a circumferential direction, of a portion where an other end of the connection pipe is to be connected to the second coil may be exposed to arc columns, respectively.
Still optionally, the connection pipe may be formed with a plurality of through holes, each of which is exposed to an arc column. With such a structure, an edge portion of each of the through holes and one of the first and second coils located at each of the through holes are heated and melted.
According to another aspect of the invention, there is provided another method of manufacturing a treatment instrument of an endoscope. The treatment instrument may include a first coil and a second coil that is different from the first coil and to be connected to the first coil, an operation wire, and a treatment device secured to a distal end of the first coil. The wire may be inserted through the first coil and the second coil, a distal end of the wire being connected to the treatment device. The treatment device can be driven by the wire when the wire is moved in the first coil and the second coil. The method includes generating an arc column between a contact portion where a proximal end side of the first coil and a distal end side of the second coil contact with each other and an electrode located in the vicinity of the contact portion, the proximal end side of the first coil and the distal end side of the second coil located at the contact portion being melted as exposed to the arc column, and solidified as cooled.
Optionally, a plurality of positions, along a circumferential direction, of the contact portion are exposed to arc columns, respectively.
Further optionally, the first coil may include a flexible coil, and wherein the second coil includes a rigid coil.
According to another aspect of the invention, there is provided a further method of manufacturing a treatment instrument of an endoscope. The treatment instrument may includes a first guide coil, an operation wire, and a device to be operated, the wire being inserted through the first guide coil, a distal end of the wire being connected to the device, the device being driven by the wire when the wire being moved in the first guide coil. The method may include inserting the first guide coil into a first cover coil, and exposing a plurality of portions of the first cover coil at positions where the first cover coil covers the first guide coil to arc columns, respectively. In this case, the first cover coil and the first guide coil at portions exposed to the arc columns can be melted, and thereafter, solidified.
Optionally, the exposing includes locating an electrode at each of the plurality of portions, and applying a predetermined voltage between the first cover coil and the electrode to generate the arc column therebetween.
Still optionally, the instrument may be a biopsy forceps having a pair of cups that is opened/closed by operation of the operation wire.
According to a further aspect of the invention, there is provided a method of manufacturing an endoscope. The endoscope may include a first guide coil, and an operation wire, the wire being inserted through the first guide coil, a distal end portion of the endoscope being provided with a moving mechanism, a distal end of the wire being connected to the moving mechanism, the moving mechanism being driven by the wire when the wire being moved in the first guide coil. The method may include inserting the first guide coil into a first cover coil, and exposing a plurality of portions of the first cover coil at positions where the first cover coil covers the first guide coil to arc columns, respectively. The first cover coil and the first guide coil at portions exposed to the arc columns can be melted, and thereafter, solidified.
Optionally, the exposing includes locating an electrode at each of the plurality of portions, and applying a predetermined voltage between the first cover coil and the electrode to generate the arc column therebetween.
According to another aspect of the invention, there is provided a further method of manufacturing an endoscope, which includes an insertion tube to be inserted in a human cavity, a bendable unit provided on a distal end side of the insertion unit, the bendable unit being operated by a pair of operation wires, and a connection member that connects the insertion tube with the bendable unit, the connection member having substantially a cylindrical shape. The method may include positioning a guide coil that covers the operation wire to elastically reinforce so that a bendable unit side end of the guide coil contacts an inner surface of the connection member, and exposing the connection member to an arc column so that the connection member and the outer surface of the guide coil being heated and melted.
Optionally, at least one through hole is formed on a side surface of the connection member. The at least one though hole may include a plurality of through holes, which are aligned in a axial direction of the connection member. Further, the exposing includes positioning a tip end portion of the guide coil at the at least one through hole, and exposing the at least one through hole to an arc column to melt the connection member and the guide coil at a position corresponding to the at least one through hole.
Further, the exposing may include connecting an electrode to the guide coil, located another electrode in the vicinity of at least one of the though holes, and applying a predetermined voltage between the electrode and the another electrode to generate an arc column therebetween.
According to a furthermore aspect of the invention, there is provided a method of manufacturing a brush instrument for an endoscope. The brush instrument may include a brush unit and an operation wire, the brush unit being secured to a distal end portion of the operation wire. Such a method may include heating a tip of the wire so that the tip of the operation wire is melted, a substantially hemispherical portion being formed thereat, and cooling the melted portion of the operation wire.
Optionally, the heating may include exposing the tip of the operation wire with an arc column. Alternatively, the heating may includes exposing the tip of the operation wire with a laser beam.
According to another aspect of the invention, there is provided a further method of manufacturing a brush instrument for an endoscope. The brush instrument may include a brush unit and an operation wire, the brush unit being secured to a distal end portion of the operation wire. The method includes inserting a tip end of the operation wire in a collar member, the operation wire protruding from the end of the collar by a predetermined amount, heating the tip of the operation wire protruding from the collar so that the tip of the operation wire is melted, a substantially hemispherical portion being formed by the melted portion of the operation wire, and cooling the melted portion of the operation wire.
The heating may include exposing the tip of the operation wire with an arc column. Alternatively, the heating may include exposing the tip of the operation wire with a laser beam.
According to a further aspect of the invention, there is provided another method of manufacturing a treatment instrument for an endoscope. The instrument includes an operable member protruded from the distal end of the endoscope, the operable member being driven by moving an operation wire inserted in the endoscope. The method may include securing the operable member onto a support member that restrict movement of the operable member, covering the operation wire with a coil, and connecting the tip end of the coil and the supporting member in accordance with arc welding.
Optionally, the supporting member may have a cylindrical portion, inner diameter of the cylindrical portion being substantially the same as an outer diameter of the coil, and the arc welding may be performed with inserting the tip of the coil in the cylindrical portion.
Further, the cylindrical portion may be formed with at least one through hole pierced in a radial direction, and wherein the tip end portion of the coil and the supporting member are connected by welding at a position where the at least one through hole is formed.
Furthermore, the at least one through hole may include a plurality of through holes distributed in a circumferential direction.
In a particular case, the treatment instrument may be a forceps provided with a pair of forceps cups.
According to a further aspect of the invention, there is provide a method of manufacturing a treatment instrument for an endoscope. The treatment instrument may include a treatment unit and an operation wire, the treatment unit being secured to a distal end portion of the operation wire, the wire being covered with a coil. The method may include heating a tip of the wire so that the tip of the operation wire and tip of the coil are melted and connected, and cooling the melted portion of the operation wire and the coil.
Optionally, the heating may include exposing the tip of the operation wire and coil with an arc column. Alternatively, the heating may include exposing the tip of the operation wire and coil with a laser beam.
In a particular case, the treatment unit may include a brush unit.
According to another aspect of the invention, there is provided a method of manufacturing a treatment instrument for an endoscope. The treatment instrument includes a treatment unit and an operation wire, the treatment unit being secured to a distal end portion of the operation wire, the wire being covered with a coil at a portion on a proximal end side with respect to the treatment unit. The method may include widening a pitch of the coil at a position a predetermined length spaced from the tip end of the coil to form an interstice portion, heating the coil and the wire at the interstice portion so that the coil and the corresponding portion of the operation wire are melted and connected, and cooling the melted portion of the operation wire and the coil.
Optionally, the heating includes exposing the interstice portion of the coil and the corresponding position of the operation wire with an arc column.
Alternatively, the heating may include exposing the interstice portion of the coil and the corresponding position of the operation wire with a laser beam.
In a particular case, the treatment unit may include a brush unit.